Suspension for use in inoculating plants with ergot



- Patented June "25, 1946" v UNITED -srA'rss PATENT orrics SUSPENSION FOR use m INOCULATING i PLANTS wrrn Eaoo'r Ralph W. Lewis, East Lansing, Mich assignor to Michigan State Board of- Agriculture, East Lansing, Mich., a corporation: oi' Michigan No Drawing. Application April 1, 194's, Serial No. 481,495

. 1 I Q I g This invention relates to the artificial infection of plants with the disease of er'got. More par-..

sclerotia are eaten, whatls known as ergotismfis developed in the animals which consume the sclerotia. On the other hand, certain drugs are producedpfrom the sclerotia which have definite therapeutic properties.

In-the United States thedisease is not particularly prevalent, principally because of unfavorable climatic conditions. Even where it occurs in such quantities as to make the plants or their seed unfit for use as feed, the percentage I y no in the suspension and there y permits the sus-;

of infection is not usually sufiicient to make it worthwhile to harvest the ergot sclerotia themselves. The separation of small quantities of the sclerotia from the harvested grain, or the hand picking of the sclerotia in the field, is not usually economically feasible.

Attempts have been made topropagate and disseminate ergot spores so as to produce a yield of ergot sclerotia that is profitable to harvest. Those attempts have not been successful from a commercial standpoint. The usual practice has been to provide a liquid spray containing the spores in suspension andspray the plants at the time of bloom. As each plant has many florets, each floret is open but a few' hours, andthe florets bloom at diilerent times, the spraying must be done irequentlyover a period of several days.

In addition, the spore suspensions are made up from laboratory cultures which must be ready for use shortly before the plants are to be sprayed.

Otherwise the percentage of germination of spores decreases to the point where the suspension becomes ineiiective as aninoculating agent.

Accordingly, the principal object of the present i invention is to provide an ergot spore suspension 2 Claims. (o1. 195-56) 30 to fioret.

. 2 I g of erg'ot spores and hyphae in a relatively con centrated solution of sugar and water. Preferably the concentration is approximately45% to 60% sugar by weight, but efiective results have 5 been attained with a percentage as low as 5% of sugar. A 5% sugar solution will prevent death of the spores upon desiccation, but will not inhibit germination. About 26% or more sugar is required to inhibit germination. Therefore the suspension, if made up long prior to use, should be of a concentration of at least sugar. The solution can be dilutedwhen ready for use to not less than 5% sugar. The. suspension is sprayed on the plants when they come into bloom,

15 and nature is then permitted to complete the cycle. a e a The higher concentration of sugar solution is particularly effective because it inhibits germination of the spores during the, time they are kept pension .to be made up long fore it is needed.

It prolongs the life of the spores after they have been sprayed on the plants by preventing desiccation thereof. Also, after it has been sprayed on 9.5 the plants it attracts insects which are important agents in the dissemination of the spores. The

uninfected florets as the insects move from floret To prepare a suspend on for use I first surface sterilize a number of 'ergot sclerotia'by dipping them in alcohol momentarily and then permit them to dry. 'The sterilized sclerotia are next cut into relatively small pieces and the pieces are planted in small dishes containing a sterile agar medium composed of agar, potato broth and sugar.

The dishes are kept covered at room temperature for a few days and during this time there 40 grow out of the pieces of sclerotia a'series of fllaments known as hyphae.

After the filaments have developed to a certain extent, segments thereof are transmitted to a suitable container which is bacteriologlcally sealed I which materially increases the length of life of and which contains organic matter-upon which Another object is to provide a spore suspension,

which when sprayed on the plants, will attract insects.

Briefly, the invention comprises a suspension is paragraph, water is poured into the container the fungus can'igrow. This organic matter may 'as. wheat, or agar Jelly, or othertypes'of vegetable matter. The containers are. maintained in a sealed condition for two or four weekslor longer.

During-this time thenumber' of ergot'spores'are multiplied many times.- 1

After .the. spores have been permittedto develop for the period mentioned inthe preceding andthe mixture of water, organic matter and spores is vigorously shaken to tree the spores from the organic matter. The mixture is then poured into a strainer, such as a 30 mesh screen, to remove large particles which might plug the sprayer when the suspension is used. The suspension of spores inwater is then added to a concentrated not less than 5% of sugar. Preferably the spraying process is repeated three or four times at intervals of a few days, so as to infect florets which are late in coming into bloom.

Once the plants have been infected, the rest of the cycle in the development of the ergot sclerotia is a natural process. When the sclerotia have been fully developed they may be hand picked or may be harvested by the usual harvesting machinery, with the grain separator set to carry the s cler0tia in with the grain rather than blow it out with the chafl and straw. Most of the sclerotia can be separated from the grain by screening through a coarse screen and then the remaining mixture of sclerotla and grain can be separated by hand.

Thus it will be seen that the invention provides a highly effective medium for artificially infecting plants with ergot.

The scope of the invention is indicated in the appended claims.

I claim:

1. An erect spore suspension for storing a culture of ergot spores until used to inoculate plants with the disease of ergot consisting of ergot spores,

ergot mycelium, commercially pure refined sugar and water, the sugar content of the suspension being at least 25% by weight.

2. The method of preparing an ergot spore suspension for use in infecting plants with the disease of ergot which consists of the following steps: first preparing a sterile culture of ergot, thereafter preparing from the culture an aqueous suspension of ergot spores, and subsequently adding a concentration of commercially pure refined sugar in an amount suflicient to bring the sugar concentration in the suspension'to at least 25%.

RALPH W. LEWIS. 

